a. Madagascar is the home to all lemurs. They are only found there and a few islands off the coast of Africa. However, they live in a variety of habitats on those islands. Some lemurs live in moist, tropical rain forests and others in dryer areas like the desert or woodlands. The majority of lemurs spend their time in trees or bushes, hanging off branches. Others, like the ringtail lemur spends time on the ground. There are also nocturnal lemurs that are active at night and tend to stay alone.
b. There are many types of lemurs. The Indri and Diademed Sifaka lemurs are the largest and can weigh up to 15 lbs. The species of the black lemur tend to weigh about 7-9 lbs and have a body length of 22-26 inches. The smallest of lemurs is the pygmy mouse lemur and only weighs an once. On average, male and female lemurs are the same size. They measure about 1.39 ft for body size and weigh between 4-5 lbs. In the wild, it is rare for female ring-tailed lemurs to live past 16 years of age and the oldest known wild female was between 18 and 20 years old. Male life span is even less because of the social system, but have been recorded living to at least 15 years of age. Both male and female ring-tailed lemurs have scent glands. Male ring-tailed lemurs have darkly colored scent glands on the inside of their wrists and on their chests and also have spurs. Lemur sexual dimorphism is usually exhibited through different coloring.
c. Lemurs are "opportunistic omnivores" which mean they eat ripe fruits, leaves, leaf stems, flowers, flower stems, exudates, spiders, spider webs, caterpillars, cicadas, insect cocoons, birds, chameleons, cicadas, grasshoppers, and even dirt from termite mounds. To get this supply, one of their most important sources are the tamarind trees. I presume their small size makes it easy for them to scurry up trees and also get a lot of forest cover.
Sources:http://www.eskeletons.org/index.html,
http://pin.primate.wisc.edu/factsheets/entry/ring-tailed_lemur, http://tigerhomes.org/animal/lemurs.cfm, http://science.jrank.org/pages/3903/Lemurs-True-lemurs.html
Spider Monkey (New World Monkey/Platyrrhini)
a. Spider monkeys have a wide geographical distribution but can be found mostly in the tropics of Central and South America. Some also live in Brazil and the Andes mountains. Spider monkeys do not live on the ground. They live from tree to tree. They thrive in the upper canopy so they compete less with other primates on the ground.
b. They do not have thumbs however they can still grip tree branches without any limitations. They have prehensile tails which is used like an extra hand. There is a patch of skin that they have at the end of their tails which works like a finger to help increase their gripping ability. Male and female spider monkeys look similar. Males have the body length of 38-48 cm, a tail length of 63-82 cm and weighs about 9-10 kg. Females have the body length of 42-57 cm, a tail length of 75-92 cm and weighs 6-8 kg.
c. The lack of an opposable thumb is a result of their environmental adaptation. It is due to them being accustomed to travel from tree to tree in their arboreal surroundings where a thumb is not usually needed. Their tail is also another feature that helps them live their arboreal life. While they are climbing, swinging and gripping with their tail, it allows the hands to be free to gather food.
Sources:http://rainforest.montclair.edu/pwebrf/rainforest/Animals/mammals/spidermonkey.html, http://www.macalester.edu/~montgomery/spidermonkey.html, http://www.honoluluzoo.org/spider_monkey.htm, http://www.animalcorner.co.uk/rainforests/spidermonkey.html
Baboon (Old World Monkey/Cercopithecidae)
a.Baboons usually live in groups or "troops" and settle in African woodland savannas. There are some that live in Arabia. They mostly live on the ground because they do not have gripping tails but they do still climb trees to sleep or eat. They prefer the semi-arid weather of the savannas but some still do live in the tropical rain forest.
b. There are five different species of baboons. On average, the males of different species are usually 33 to 82 pounds. Baboon bodies are 20 to 40 inches long, not including tails lengths. Females are half the size of males.
c. Since baboons are flexible and can find food anywhere from the ground, the trees, even underground, they are able to adapt to varying habitats with their strategies. They are able to extract food and nutrients from almost all strata of the environment.
sources: http://www.eskeletons.org/index.html, http://pin.primate.wisc.edu/factsheets/entry/olive_baboon, http://animals.nationalgeographic.com/animals/mammals/baboon/
Gibbon (Lesser ape/Hylobatidae)
a. Gibbons are arboreal, so they live in the trees. They mostly inhabit northern India and the islands of Indonesia.
b. There are 12 species of gibbons and are generally not sexually dimorphic in size. Females usually weigh more than mature males. They have very long arms and use them for a swinging locomotion called "brachiation". They also have very long hands and fingers. Gibbons are small and lightweight and grow to be around 90cm tall and weigh just 7kg. They look similar besides the differing colors.
c. Since gibbons are lightweight, they are able to move around and leap between the trees. Their small size also makes them more swift. Plus, their arms allow them to have a long reach. Living in the trees is also beneficial to them because the trees provide them with plenty of food supply.
Chimpanzee (Great ape/Hominidae)
a. Chimpanzees live in groups and inhabit most of Central and Western Africa. They can live in places ranging from humid rain-forests to swampland to grasslands to woodlands. They make nests made out of leaves and plants for sleeping in the trees. They are known for constructing.
b. Chimpanzees are our closest relative. We share 98% genetic material. Some differences include: larger ears, more protruding face, and bigger lips. For males, their weight ranges between 75-154 lbs and 55-110 lbs for females. Their height ranges from about 3-1/4 feet to 5-1/2 feet. They don't have tails. Their arms tend to be longer than their height. They have similar hands to humans but shorter thumbs. They can pick things up with their feet.c. Chimps are able to make tools with their surroundings. They use sticks to fish and dig up termites to eat. They make hammers out of stones to crush nuts. They even use chewed up leaves to sop up water to drink. They are resourceful and intelligent.
Researching through all these primates, it really fascinated me that we humans lie in the same family tree as them. It is quite funny to say we are related to spider moneys. I also found that the environment greatly impacts each species' adaptions and their steps to evolving. Many of the primates above had to learn to live in the trees to avoid predators and protect their small bodies. Also, their small size helps them with their agility. Small details including a grasping tail or opposable thumbs definitely helps these animals survive as well.
Great discussion on body size and the presence or absence of sexual dimorphism. In the discussion of lemurs, you mentioned why their body size might benefit them in their given environment, which was excellent. I was looking for that kind of analysis with the other four primates as well.
ReplyDeleteWhy do some primates express sexual dimorphism and others don't? That is related to factors in the environment as well, such as competition for resources, territoriality, etc.